Synthesis of Tin-Doped Three-Dimensional Flower-like Bismuth Tungstate with Enhanced Photocatalytic Activity

Photocatalytic degradation of harmful organic matter is a feasible and environmentally friendly method. Bi2WO6 has become a hotspot of photocatalysts because of its unique layered structure and visible light response. In the present study, Sn doping was adopted to modified Bi2WO6 by hydrothermal method. The Sn-doped Bi2WO6 photocatalysts were characterized by XRD, SEM, TEM, BET, XPS, PL, and DRS, respectively. The results show that Sn-doped Bi2WO6 shows three-dimensional (3D) flower-like morphology, which is composed of two-dimensional (2D) nanosheets. Sn4+ ions enter into the Bi2WO6 lattice, producing a degree of Bi2WO6 lattice distortion, which is in favor of reducing the recombination of photogenerated electrons and holes. Moreover, the specific surface area of Bi2WO6 is significantly increased after doping, which is beneficial to providing more active sites. The photocatalytic results show that 2%Sn-Bi2WO6 exhibits the highest photocatalytic activity. After 60 min of irradiation, the photocatalytic degradation degree of methylene blue (MB) increases from 80.6% for pure Bi2WO6 to 92.0% for 2%Sn-Bi2WO6. The first-order reaction rate constant of 2%Sn-Bi2WO6 is 0.030 min-1, which is 1.7 times than that of pure Bi2WO6.